"Though dress is a very personal matter, it is a very public and professional matter on the job. Employees are expected to comply with company standards," she explained.

The problem is, these can be hard to decipher.

She said during her 20-plus years working as an executive coach, one of the most frequent career roadblocks she has observed is inappropriate dress in the workplace because "people don't completely understand what all the different dress codes mean."

To help, here are some examples of appropriate "business casual," "smart casual," and "boardroom formal" outfits:

Business casual

Mike Nudelman/Business Insider

There is no general agreement on the definition of the term "business casual."

"It depends on several factors including the industry, size of the company, number of employees, amount of interaction between employees and customers, geography, climate, culture, and average age of the workforce," Price said.

At most companies, however, the "business casual" dress code encourages employees to project a "professional, business-like image while enjoying the advantage of more casual and relaxed clothing," Price explains.

Appropriate business casual dress typically includes slacks or khakis, dress shirt or blouse, open-collar or polo shirt, optional tie or seasonal sport coat, a dress or skirt at knee-length or below, a tailored blazer, knit shirt or sweater, and loafers or dress shoes that cover all or most of the foot.

"The key look in this dress code is a chic, put-together ensemble," Price said. "It fashionably combines elements from the other dress codes, such as a nice pair of dark slacks, with a coordinated dressy blouse, jacket, and scarf, or a nice pair of trousers with a button-down shirt and sport coat."

Also remember to keep your hair and makeup work-appropriate ... and don't overdo it on the cologne or perfume.

Boardroom formal

Mike Nudelman/Business Insider

Being a member of the C-suite, or a business partner or guest of the C-suite, "comes with the need for some kind of tactfulness and respect — and what you wear plays a big role," Sylvie di Giusto, author of "The Image Of Leadership," told Business Insider.

When it comes to the "boardroom formal" dress code (also known as "business formal"), employees are expected to project a professional image and convey executive presence, Price added. "Most often, employees following this dress code are meeting face-to-face with customers, clients, senior management, and key stakeholders in the industry who expect and require the proper protocol of professional business attire."

The standard "boardroom formal" attire for men is a dark suit (navy, black, or charcoal), a white dress shirt, a subtle-patterned tie and socks, and black dress shoes. "I also recommend a high-quality accessory, including a wristwatch or attaché case," di Giusto said. "Less is more."

For women, appropriate boardroom attire includes either a two-piece matched pantsuit, skirt suit, or dress (hem no higher than one inch above the knee) in traditional colors such as black, navy, grey, or brown; a collared dress blouse or shell; black or neutral hosiery; closed-toe dress shoe, such as a pump; and conservative accessories, Price said.

"In general, paying attention to the visual details of your look conveys preparation, planning, and respect for those whom you meet," di Giusto added. "The way you respect yourself also sets the standards on how others will respect you."